GadgetBuilder's 7X12 MiniLathe

and Little Workshop

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Connecticut area home shop machinists are
invited to meet with our CTHSM group on 8 March 2015. (February 2015 meeting cancelled due to weather.)

My 7X12 MiniLathe, was purchased from Homier and delivered in January '03.
The picture above (Javascript required) shows one of the projects done since then - the picture links to the page if there is
one, otherwise look on this page. When I started this site the 7X12 was my only machine but I now have a couple more so I revised
the site name to accommodate this expansion. This page is a chronological list of some of my projects so new
material is mainly at the end although I revise existing pages occasionally without warning.
The left menu is a mostly alphabetical list of pages on this site. Alternatively, there is a Site Map, meant for easy navigation.
As most visitors probably know, the mother
lode of mini-lathe info is found at Frank Hoose's site.

My very first machining project was a tailstock
camlock to make it more convenient to move the tailstock. This was a good
choice for a first project since it was very easy to build and yet is a
valuable modification of the minilathe.

I added a Phase II AXA 100 QCTP. This toolpost looks huge on the minilathe
and it makes a huge difference to the way the lathe operates: easy tool height
adjustment, less tool chatter, a nice boring bar holder, and a simple mount for
the cutoff tool. In addition, it's easy to add a vise
to do simple milling: bolt a 3 inch length of 1/2 inch bar to a small vise,
then mount the bar in the tool holder - not very rigid, convinced me to get a
mill... The height is crudely adjustable using the tool height adjustment of
the toolpost. An advantage to this setup is that it takes only seconds to shift
from lathe to milling operations. The downside to the new toolpost (and there's
always a downside) is that it restricts the size of items which can be turned
due to its sheer size; I added the modified compound rest
#1777
from LMS to help accommodate this and eventually modified the
cross slide to allow more range.

This ball turning attachment to fit the
minilathe is useful in making ball handles, of course, but is also handy for
rounding bolt heads and making Lucite magnifiers.

My carriage lock is based on Mike Walsh's
design. This would make a useful second project although there is more filing,
sanding, and polishing than turning.

A taper attachment for the mini lathe; it works
better since adding struts to stiffen the mounting.

Ball bearings were added to the mini-lathe controls, beginning with the
cross slide followed by the
compound (much easier to do than the cross slide).
These ball bearings transform the "feel" of the lathe and are WELL worth
adding. The cross feed and compound dials were converted to
free spinning with friction lock easy to do, works
well, replaces the friction spring under the dial.

My original reason for getting a lathe was to make items related to my
microscope hobby but I got into fiddling with lathe related stuff. I finally
got back to optics related things by making some
Coddington magnifiers from Lucite rod. A second
Lucite project was an optical center punch
patterned after one found on Harlan's site(Disappeared 3/13).

A clamp knurler was built from Martin Cleeve's
design. His article suggests using the cross feed to knurl but this puts
considerable strain on the cross feed lead screw and nut; using the carriage
feed instead works well and puts less strain on the machine.

A discarded Nordic Trac provided a 9" hand
wheel which is helpful for tapping and for single point threading.

Nothing is wasted here at Poverty Acres -- a roller
from that Nordic Trac was adapted to prevent the discharge chute on my
mower from digging in on steep angle changes.

I made several MT2 tapers to hold commonly
used drill bits: the cheapskate's alternative to a tailstock turret.

When is a tool height gauge not a tool height gauge? When it's a
die holder -- you get two for the price of one with
this approach.

A center finder is one way to simplify use
of the mini-lathe's 4 jaw chuck.

I copied Varmint Al's idea for a tailstock flag and
meter. Used a piece of 1/2" lucite for the flag, the magnet is the rotor
from a VCR takeup motor with an aluminum bracket to mount the meter; simple,
cheap, effective. The DRO has further
simplified drilling to depth.

Made a plinth to replace the compound for most
things other than threading and tapers. This did not reduce chatter as I hoped
so I don't use it much. Eventually I figured out that retracting the compound
so the tool point is over the cross slide (not cantilevered out to the
headstock side) helps reduce chatter and the plinth I made doesn't allow
this.

A Homier mill has been added to my shop.
This doesn't fit nicely within the title of my site so I don't know exactly how
I'll work that out but after wrestling this 700 pound guy down the stairs and
onto the table, the mill stays! One necessary adjustment with a mill is
tramming. Some shop made
mill tooling; the cutter holders are from a car
axle annealed in the fireplace (the wheel spline is included on one).

A Mini-Tinker cutter grinder didn't work as I
hoped for sharpening end mills so eventually I purchased a cutter grinder (see
below) which didn't work out either...

Tool holders to fit my Phase II toolpost were
on my to-do list for a while; the new mill made many things possible.

Most tangential (diamond) toolholders
don't fit a QCTP; I adapted the Freeby design to fit my QCTP. I get a better
finish on steel with this toolholder than with regular toolholders and bits so
I now use this for most turning and facing.

I made Will Hamlyn's split nut mod to
reduce backlash in the cross slide. This didn't work as well as I hoped so I
split the old nut lengthwise instead but it cracked when squeezed so I use it
with 5 thou backlash.

One of my interests is clocks; I made a gear
depthing tool which is useful in building a clock -- something which I am
attempting at present. I added a page about my
clock project and its current state.

I got into sharpening drills of various sizes
and found one fixture won't cover the gamut -- so I wound up with three. Plus a
lever drill attachment to use all
those sharp drills.

A finger plate simplifies cross drilling of
modest size rounds, something that used to take some time to accomplish
accurately.

The purchased Universal Cutter Grinder
didn't solve my dull end mill problem that the Mini-Tinker failed to solve, so
it was returned. Eventually I built a
Brooks-Stent cutter grinder; this is more
capable than either of my earlier approaches to end mill sharpening.

I revised the depth stop on my
HF drill press (idle hands do the devil's work). This is much more useful than
anticipated, well worth doing.

Added DROs to the lathe using 6" scales. These are
more versatile and therefor more useful than I originally expected.

In making the leadscrew for the Brooks-Stent I needed a sharp threading bit
so I built the sharpening jig from
"Screwcutting in the Lathe" by Martin Cleeve. This jig makes the job fast and
easy. A little experimenting with this jig showed that it can be used to
sharpen many lathe (and shaper) bits other than threading bits and the results
are clearly better than my hand sharpening attempts.

The Broadley spindle directions call for a steady
rest so I built one to fit either the 7x12 or the Rockwell 10" by swapping
the base. Then I built the "Linerator" to add
graduations to the Brooks' dials; lots of gadgetry is needed to complete the
Brooks grinder.

I built a Geo. Thomas "Retracting
Toolholder for Screwcutting" to make threading easier and faster. I do a
fair amount of threading so I've developed a routine for it which this tool
simplifies.

Added a mechanical carriage
auto-stop to speed up threading. Combined with the retracting toolholder
this speeds up threading considerably.

Built a graver rest for the minilathe; a
collet chuck or similar is needed to use it safely.

Added a dog clutch type carriage auto-stop to
further improve threading; this provides automatic thread pickup on both
imperial and metric threads plus it eliminates need for the thread chasing
dial. I posted a video of the dog clutch in use on YouTube.